Hi, I just recently learned about pufferfish and started a pufferfish tank. They are very cute, but despite their cuteness and small size, they are fin nippers. They will shred other fish's fins w/ their beaks. So they're best kept in a species tank, meaning just dwarf puffers. You could fit one or two in a 6 gallon. Here's a link that I found helpful:
Ok...for some reason the links are acting retarded, it's httpwwwdwarfpufferscom (you can insert all the dots, that's the only way I could type it w/out it coming up as ###)